A gas turbine engine, such as a turbocharger, may be used to power aircraft, automobiles, or various other types of vehicles and systems. Turbochargers known in the art may employ high strength brass alloys for some of the components thereof. As is known in the art, a high-strength brass alloy has a matrix that may exhibit various phases such as an α phase, β phase, α+β phase, and γ phase, according to the total amount of added elements that are weighed by zinc equivalent. If the amount corresponding to the zinc equivalent is small, the matrix exhibits the α phase. A high-strength brass alloy exhibiting the α phase has superior toughness but has low hardness. If the amount corresponding to the zinc equivalent is increased, the matrix exhibits the β phase. Moreover, if the amount corresponding to the zinc equivalent is further increased, the matrix exhibits the γ phase. In a high-strength brass alloy exhibiting the γ phase, hardness is increased and wear resistance is improved, whereas toughness is greatly decreased and shock resistance is decreased.
Turbochargers current known in the art employ such alloys to manufacture the bearing components of the turbochargers. However, these alloys undesirably include a percentage of lead. Exemplary allows known in the art for such applications include CW713R available from Seeberger GmbH & Co. KG of Schalksmühle, Germany and C67400 available from National Bronze and Metals, Inc. of Houston, Tex. Due to their lead content, these prior art alloys cannot meet the Europe ELV directives requirement of lead below 0.1% by January, 2015.
Currently, the alloy C90300 tin bronze, also available from National Bronze and Metals, Inc., is a lead-free alloy that is available for use in turbochargers for commercial vehicles. However, passenger vehicles have more stringent requirements than commercial vehicles in terms of wear-resistance and thermo-physical properties. As such, C90300 is not available for use in passenger vehicle components due to these more stringent requirements, including good machinability, wear resistance, and certain mechanical properties and thermo-physical properties. Thus, the prior art remains deficient.
Accordingly, it is desirable to provide improved alloys for use in manufacturing components for use in gas turbine engines. Further, it is desirable to provide such alloys that are lead-free. Still further, it is desirable to provide alloys suitable for use in passenger vehicle application. These and other desirable features and characteristics of the disclosure will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.